Impulse generator



Jan. 26, 1965 s. H. WALLQVIST ETAL 3,156,945

IMPULSE GENERATOR 4 Sheets-Sheet 1 Filed July 3, 1961 Fig.1

Jan. 26, 1965 s. H. WALLQVIST ETAL 3,166,945

IMPULSE GENERATOR Filed July 5, 1961 4 Sheets-Sheet 2 Jan. 26, 1965 s. H. WALLQVIST ETAL 3,

IMPULSE GENERATOR Filed July 3, 1961 4 Sheets-Sheet :5

Jan. 26, 1965 s. H. WALLQVIST ETAL 3,166,945

IMPULSE GENERATOR Filed July 5, 1961 4 Sheets-Sheet 4 United States Patent Gllice 3,166,945 IMPULSE GENERATOR Sven Hakan Wallqvist, Halrnstad, and Bengt Anders Bjiirk, Getinge, Sweden, assignors to Haldex Aktiebolag, Knaredsgaten, Sweden, a corporation of Sweden Filed July 3, 1961, Ser. No. 121,676 4- Claims. (Cl. 74-142) The present invention relates to an impulse generator for generating electric impulses for feeding electrically driven counters and the like. The present invention has for its object to provide an impulse generator which exhibits a considerably higher accuracy as far as the impulse generation is concerned than previously known generators of this kind, and in which the risk of generating double impulses or series of impulses is considerably reduced.

An impulse generator according to the invention comprises a swingably mounted lever for cooperation with an impelling mechanism, such as a cam disk, eccentric or the like, and is chiefly characterized by the feature that the free end or" the lever is provided with a further lever which is pivoted to said end and whose one free end co-operates with a member that actuates electric contacts for completing the current circuit of the advancing mechanism of the counter, a member entrained in the operational movement of the counter being adapted to actuate said further lever so that its actuation of the contact members is caused to cease as soon as the advancement of the counter is completed.

According to the invention said further lever is also adapted to co-operate with a retardation mechanism, the lever before starting the advancing movement of the retardation device resting on a bridge or a wing adjusted in such a way that the free end of said further lever after leaving said Wing will directly engage the proper ratchet tooth or the like.

The present invention will be described in greater detail with reference to the attached drawings.

FIG. 1 shows, in perspective, a counting mechanism or counter provided with an impulse generator according to the present invention. FIG. 2 is an elevation of the impulse generator in its starting position. FIG. 3 shows the impulse generator in an initial stage of operation. FIGS. 4-7 show the impulse generator during further stages of operation which will be disclosed in greater detail in the following description.

FIG. 1 shows a taximeter counter l and a device stepwise advancing the counter, which device has the form of a pulling electromagnet 2. The latter is intended to be energized through a contact device 3 comprising two leaf springs 4 and 5 provided with contact members and forming switch means. Said contact device or electric switch means is adapted to be actuated by an impulse generator generally designated by 6. All details now mentioned are carried in a frame 7. The impulse generator comprises a double-armed primary lever 9, which is swingably carried on a pin 8 and the free end of which is provided with a lug 10 for coacting with an impelling mechanism, such as a star wheel or cam disk 11,,driven in the conventional way by a clockwork and/or the Vehicle. The lever 9 is kept in contact engagement with said cam disk 11 by means of a spring 12 whose one end is secured to a pin 13 on the frame 7 and whose opposite 3,166,945 Patented Jan. 26, 1965 end is secured to the outer free end 14 of the lever 9. The lever 9 is also provided with a projecting portion 35 for coacting with a reset mechanism (not shown). The opposite end 16 of the primary lever 9 is provided at its outer end with a pin 17 to which a lever 18 form ing a pawl element is pivoted. Said lever or pawl element 18 is double-armed, thet two arms being substantially perpendicular to one another. One arm 19 or" the lever 18 is provided at its end with a lug 20 which is arranged, in the starting position of the lever 9, to bear on a Wing or bridge 21 mounted on the frame 7. Under normal operating conditions (that is, when so called retardation is not occurring), the lug 2% on arm 19 is intended to co-operate with the outer end 22 of a doublearmed lever 23 which may be called the switch operating member carried on a pin 24 mounted on the lever 9, adjacent the pin 8. The opposite free end 25 of the lever 2-3 is provided with a pin 26 having an insulating bush 2". Said pin as is intended to co-operate with the contact spring 4 for making and breaking the contact device 3.

A shaft 28 is connected in synchronism with the mechanism (not further shown) which advances the counter intermittently and which is therefore actuated by the electromagnet 2. Said shaft is provided with an arm 29 spring-urged by means of a spring 30 secured to the pin 13. Said shaft is also provided with a further arm 31 which may be called a release arm, adapted to coact with a second arm 32 of the lever or pawl element 18 to actuate this lever, when the advancing mechanism of the counter has completed its adjusting movement, in order that the lug 2t? disengages the end 22 of the switch operating lever 23, whereby the current through the electromagnet is interrupted by the springs 4, 5 separating the contacts of the switch means. Said second arm 32 of the lever or pawl element 18 is also adapted to coact with a fixed stop member 33 on the frame for raising the arm 19 when resetting the device by movement of lever 9 clockwise about pin 8, so that the lug will rest upon the wing 21.

Below the wing 21 and beside the lever 23 is a retardation mechanism, generally denoted 34, rotatably mounted on the frame. The retardation mechanism consists of two ratchet Wheels 35, 36, which are fixedly mounted in relationship to one another on a disk 37 and rotatably carried on a stub shaft 38. A detent disk 39 is also rotatably mounted on the stub shaft 38, said detent disk being provided with holes 40 for locking engagement with a detent spring member 41. The ratchet wheels are spring-urged for rotation in the direction shown by the arrow 42, the inner ratchet wheel being intended for co-operation with a stop (not shown) provided on the detent disk 39 for establishing a predetermined starting position for the device in relation to the detent disk. The ratchet wheel 35 is also arranged to co-operate with a pawl (not shown) which is adapted to be released from its engagement with said ratchet wheel upon resetting the device. The wing 21 is disposed in such manner in relation to the ratchet wheel 36 of the retardation device that, when the lug 20 leaves said wing upon movement of the lever 9, said lug automatically falls down to engagement with a selected gap of tooth below. As shown in the drawing the depth of the gaps of tooth is such that the lug 20 will not engage the free end 22 of the lever 23 as long as it remains in engagement with one of the gaps of ratchet wheel 36. The ratchet wheel 36 is also provided with a large recess 43, into which the lug 21) will fall after carrying out the retarding operation so as to come into co-operation with said end 22 of the lever 23. It is clear that the setting of the ratchet wheel can be selected so that the pawl element 21) always falls in large recess 43, in which case there is no retardation action.

The impulse generator operates in the following way.

Let it be assumed that the various parts are in a starting position as shown in FIG. 2. It is then pie-supposed that the resetting mechanism actuating the projecting portion 15 is relieved. The lug now engages the outermost cam portion of the cam disk 11. The lug 24B of the shank 19 rests on the wing 21 and the retardation device 34 is in its starting position, while the retardation may be set, as pointed out above, from a no retardation position to a rotation corresponding to the total number of teeth of ratchet wheel 36, in the present case set as an illustration for a retardation corresponding to one tooth. The contact springs 4- and S are separated, the current circuit of the electromagnet thus being broken. The cam disk 11 is assumed to rotate in the direction shown by the arrow 44.

As seen in FIG. 3, upon further rotation of the cam disk, the lug 10 will fall down against the bottom portion of the cam disk curve, and in so doing the primary lever 9 will thus change its position. The pawl lug 25 will leave the wing 21 upon which the lever 18 is swung so that the lug falls down into a gap between the two preselected underlying teeth of the ratchet wheel 36, in this case the teeth adjacent to the recess 43. This falling movement takes place during an initial stage of motion of the primary lever 9. During the further motion of said lever, while the lug 10 approaches the bottom of the curve, the ratchet wheels are actuated by the arm 19 through the pawl lug 20 so that they turn an angle essentially corresponding to one tooth. Thereupon the wheel 35 is locked in this position by the previously mentioned pawl, not shown. The lug now rests on the bottom of said gap of tooth and Will thus not actuate the switch operating member 23, for which reason the contacts are still unaffected.

During the further rotation of the cam disk, the lug 10 will again coact with the top of the camming surface of the disk, the lever 9 once more assuming the position shown in FIG. 2. However, as seen from FIG. 4, the lever 18 will assume a position different from that shown in FIG. 2. By the swinging motion of the lever 9 the lug 20 has been Withdrawn from said gap of tooth, it has moved across the tooth adjacent the recess 43, and then it has fallen down into said recess. In doing this, the lug has come into engagement with a notch in the end 22 of the lever 23. The retardation mechanism has now ceased to affect the further function of the device, although the lug 20 engages the ratchet wheel 36 in the recess 43.

In FIG. 5, the cam disk has now turned to a position such as that of FIG. 3. By the fact that the lug 10 has lost its contact with the top of the curve the lever 9 will swing, which causes the lever 23 to swing, through the intermediary of the arm 19 and lug 20. By the swinging of the last mentioned lever the pin 26 will cause the contact spring 4 to make contact with spring 5. The circuit of the electromagnet will then be completed. This causes the electromagnet to be activated, which causes the arms 29 and 31 to be turned and the spring 30 to be tensioned. When-the electromagnet approaches the end of its stroke, the pawl for advancing the counter will engage a certain tooth of an advancing wheel. The last mentioned members are not shown. In the stage of motion in question, the arm 31 has arrived into engagement with the arm 32 of the lever 13 (see FIG. 6). The lever 18 is then rotated so that the lug 20 disengages the notch in the end 22 of the lever 23, the end 22 being swung back under the action of springs 4, 5 to a position wherein separation of the contacts break the electromagnet circuit. After the current has been interrupted and under action of the spring 30, the electromagnet, and thus also the arm 31, returns to its starting position while advancing the counter one step. By the mechanism according to the invention there is also attained an extremely short on-time for the electromagnet which results in that the winding of the magnet may be dimensioned for a comparatively high power with the resulting large pulling effect of the electromagnet.

In the further rotation of the cam disk 11 the lever 9 will be turned, so that the lug 20 will slip back on the top side of the end 22 of the lever 23 until it again falls down into the notch 43, which occurs when the top of the cam disk co-operates with the lug 10, as shown in FIG. 7. An operating cycle has now been completed and the position of FIG. 7 corresponds to that of FIG. 4.

For resetting or restoring the device to the starting position shown in FIG. 2, the lever 9 is turned, by means of the resetting mechanism engaging the portion 15, to such an extent that the arm 32 strikes the stop member 33, in doing which the lever 18 is rotated so far that the lug 20 is raised above the level of the Wing 21. The wing 21 is resiliently supported and is adapted, in said movement of the lug 20, to be displaced laterally by said lug during the passage of the latter. When the lever 9 moves back, the lug will thus slide down onto the top side of the wing 21. In the resetting manipulation, the pawl of the ratchet wheel 35 is also actuated so that the retardation mechanism returns to its starting position.

It will be appreciated that by a construction according to the invention a double generation of impulses is effic1ently avoided as the lever 23 actuating the contacts is not directly connected to the lever 9 actuating the cam disk 11. Furthermore, by provision of the lever 18 an accurate transmission and interruption of impulses is accomplished, and by means of the wing 21 an accurate engagement with the intended gap of tooth of the ratchet wheel 36 is always attained, which is of essential importance for obtaining invariably the same charging of the fundamental travelling distance or the correspondin time What we claim is: a l

1. In an impulse generator for electric counters and the like having a frame, a first pivot on said frame, a primary lever pivotally mounted on said first pivot, a paw-l element pivotally mounted on said primary lever at a point remote from said first pivot, a rotatable cam disk mounted on said frame positioned to contact said primary lever to cause pivotal movement of said primary lever whereby said pawl element is oscillated, biasing means holding said primary lever against said cam disc, means to rotate'said cam disc, a switch operating member mounted to be operatively engaged by said pawl element to be moved thereby as said primary lever moves in one direction, an electric switch means, said switch operating member including means to actuate said switch means when moved by said pawl element, a second pivot on sa1d frame, an arm pivotally mounted on said second pivot operatively connected to said means to rotate said cam (C to periodically move said arm, said arm being positioned to contact said pawl element upon movement of said arm whereby said arm is pivoted on said second pivot to disengage said pawl element from said switch operating member.

2. The device of claim 1 in which said switch operating member is pivotally mounted on said primary lever.

3. The device of claim 1 in which a fixed stop is provided in a position to be engaged by said pawl element when said primary lever is pivoted to a position away from said cam disc to move said pawl element into a re-' set position.

4. The device of claim 3 in which a retardation device is provided in a position to be engaged by said pawl element and to hold said pawl element out of engagement with said switch operating member, said retardation device including a ratchet wheel adapted to be progressed step by step by said pawl element as it is reciprocated by said primary lever, said ratchet wheel being provided with a deep notch in its periphery forming a recess such that when said pawl element engages in said notch it will also engage said switch operating member, and a lug mounted on said frame positioned to engage and support said pawl element when said primary lever is pivoted away from said cam disc whereby said retardation device may be reset.

'5 References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCES IBM Technical Bulletin, vol. 4, No. 2, page 18, July 1961.

BROUGHTON G. DURHAM, Primary Examiner. 

1. IN AN IMPLUSE GENERATOR FOR ELECTRIC COUNTERS AND THE LIKE HAVING A FRAME, A FIRST PIVOT ON SAID FRAME, A PRIMARY LEVER PIVOTALLY MOUNTED ON SAID FIRST PIVOT, A PAWL ELEMENT PIVOTALLY MOUNTED ON SAID PRIMARY LEVER AT A POINT REMOTE FROM SAID FIRST PIVOT, A ROTATABLE CAM DISK MOUNTED ON SAID FRAME POSITIONED TO CONTACT SAID PRIMARY LEVER TO CAUSE PIVOTAL MOVEMENT OF SAID PRIMARY LEVER WHEREBY SAID PAWL ELEMENT IS OSCILLATED, BIASING MEANS HOLDING SAID PRIMARY LEVER AGAINST SAID CAM DISC, MEANS TO ROTATE SAID CAM DISC, A SWITCH OPERATING MEMBER MOUNTED TO BE OPERATIVELY ENGAGED BY SAID PAWL ELEMENT TO BE MOVED THEREBY AS SAID PRIMARY LEVER MOVES IN 